Glossary

Definitions and explanations of some terms used in the pages of the site. The Wikipedia icon () followed by a word or phrase in small boldface is a link to an appropriate Wikipedia article.

A

B

U.S. Navy designator for a Battleship. Large, heavily armed and armored, the battleship was the premiere capital ship of naval fleets before the introduction of the aircraft carrier. Battleship

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The front end of a boat or ship.

C

U.S. Navy designator for a Heavy Cruiser. Smaller than a battleship and more lightly armed, but usually faster. Cruiser

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Caliber. When used in reference to ship weapons, defines the length of the barrel in multiples of the weapon's bore. A 5"/50cal gun has a bore (shell diameter) of five inches and a barrel length of 20 feet 10 inches (5" x 50 = 250"). When used in reference to smaller weapons, defines the diameter of the round fired in hundredths of an inch. A 50 cal machinegun fires a round 1/2 inch (.50") in diameter. Caliber

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Combat Air Patrol. Fighters launched to orbit above a carrier task group to intercept and destroy incoming enemy aircraft.

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Large, heavily-armed warships. While there is no generally-accepted definition of the term, it is usually taken to mean the primary combat ships of a fleet. A general rule-of-thumb is that a capital ship is any warship that displaces 20,000 tons or carries 12" guns, usually battlecruisers and battleships. Heavy cruisers are not considered capital ships. During World War II, the fleet aircraft carrier, with it's ability to project force several hundred miles, joined the ranks of capital ships. Light carriers are not considered capital ships; the dividing line seems to be the number of aircraft carried. Capital Ship

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Title of the officer in command of a ship, regardless of rank. Even if the commanding officer is an Ensign, he or she is referred to as "Captain". As there can be only one Captain on board a ship, other officers who may hold the rank of Captain used to be socially promoted in conversation; a Marine or Army Captain would be called "Major", a Navy Captain would be referred to as "Commodore". This practice has declined in recent years.

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U.S. Navy designator for a Guided Missile Cruiser. Basically an updated heavy cruiser, using guided missiles as primary weapons.

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U.S. Navy designator for a Light cruiser. Smaller and more lightly armed and armored than a heavy cruiser.

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U.S. Navy designator for a Light Cruiser (Anti-aircraft). A light cruiser with an extensive anti-aircraft weapons fit, occasionally at the expense of direct-fire weapons.

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Nominally, a group of ships built to the same design. The class is usually named for the first ship of the group to have it's keel laid, although the name of the first ship launched may be used instead. Class names may also be used to designate sub-groups of a given class of ships, based on modifications of the original design, major refits, or conversion to other missions. Ship Class

D

U.S. Navy designator for a Destroyer. A small, lightly-armed ship designed to defend the fleet against smaller threats, such as enemy torpedo boats. The original name of the class, in fact, was "torpedo boat destroyer". Destroyer

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U.S. Navy designator for a Destroyer Escort. About the size of a destroyer, but more lightly armed and slower, these ships were intended for use as convoy escorts and anti-submarine ships. Destroyer Escort

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All U.S. Navy ships carry a code known as a designator. This consists of a set of letters indicating the ship's class or type followed by a hull number. Hull classification symbol

The list below defines the various class designations usually encountered when referring to carriers and aviation ships. These definitions are taken from several sources, and should not be considered "official". Other countries use different standards for their ships' designators, or none at all.

ACV	Auxiliary Aircraft Carrier. Designation applied to escort carriers before they were reclassified as combat vessels.
AKV	Cargo Ship/Aircraft Ferry
AVG	Escort Carrier, Auxiliary (non-combat ship)
AVT	Auxiliary Aircraft transport (although AVT-16 USS Lexington carried this designation during the last part of her service as a training carrier)
CV	Carrier, Fixed-Wing Aircraft (Fleet Carrier). Usually carries about 90-100 aircraft.
CVA	Attack Aircraft Carrier
CVAN/CVA(N)	Attack Carrier, Nuclear Power
CVB	Battle (Heavy) Aircraft Carrier. Larger than a fleet carrier, this designation was only applied to the Midway-class carriers.
CVE	Escort Carrier. Small, slow, unarmored and lightly armed, usually carrying only a single squadron of aircraft (12-15 planes). Sometimes referred to as "Combustible, Vulnerable and Expendable."
CVHE	Escort Helicopter Carrier. An escort carier converted to operate as a helicopter carrier in support of amphibious operations.
CVL	Light Aircraft Carrier. Smaller and slower than a fleet carrier, with a smaller number of aircraft; about two squadrons (24-30 planes).
CVN/CV(N)	Aircraft Carrier, Nuclear Power
CVS	Anti-Submarine Warfare Carrier. An aircraft carrier with specialised training and equipment to detect and attack submarines.
CVT	Training Carrier. An aircraft carrier permanently assigned to training duties.
CVU	Utility Aircraft Carrier. A carrier, usually a CVE, assigned to move aircraft between locations, while still retaining the capability to operate the aircraft.
IX	Unclassified Miscellaneous. A ship that does not fit into any other type designation, usually a one-off special purpose ship. The historic USS Constitution, a three-masted sailing frigate, is maintained as an active U.S. Navy vessel and used to carriy an IX designation (IX-21).
LHA	Amphibious Assault Ship, General Purpose
LHD	Amphibious Assault Ship (with a "wet deck" for launching and recovering landing craft and/or air-cushion vehicles (ACV))
LPH	Amphibious Assault Ship

These designations are subject to change, as a ship is modified or it's mission changes. Occasionally, the U.S. Navy will redesignate an entire group of ships. Some of these mass redesignations are listed below. Where possible, these changes are reflected in the individual ship data tables.

20 August 1942	Escort carrier designations were changed from AVG to ACV.
15 July 1943	The U.S. Navy revamped its designations of carriers, reserving CV (Aircraft Carrier) for CV-3 USS Saratoga, CV-6 USS Enterprise and the Essex-class; CVB (Aircraft Carrier, Large) for the 45,000 ton class then under construction (the Midway-class); and CVL (Aircraft Carrier, Small) for the 10,000 ton class based on light cruiser hulls (the Independence-class). The same change took escort carriers out of the auxiliary vessel category (ACV) and redesignated them as combat ships (CVE).
1 October 1952	The U.S. Navy again reclassified its carriers. Those designated CV and CVB were reclassified CVA (Attack Carriers).
12 May 1955	Classification system revised, adding Escort Helicopter Aircraft Carrier (CVHE) and Utility Aircraft Carrier (CVU).
29 May 1956	Classification system modified to include suffix (N) to designate nuclear power.
7 May 1959	The classification of 36 escort carriers, designated CVE, CVU, and CVHE, was changed to AKV, Cargo Ship and Aircraft Ferry. The change was accompanied by a change in hull numbers and marked the end of the escort carrier as a combatant ship in the U.S. Navy.
15 May 1959	The classification of four support carriers (CVS) and seven light carriers (CVL) was changed to Auxiliary Aircraft transport (AVT). This change removed the CVL designation from the Navy Vessel Register.

In The Carrier Project, ships will usually be identified by their most common or most recognisable designation, regardless of the actual designation they carried at the time. For example, fleet carriers will be referred to as "CV-xx" and escort carriers as "CVE-xx".

E

F

G

H

His Imperial Japanese Majesty's Ship. A commissioned ship in the Japanese Navy; i.e. HIJMS Yamato. This prefix was not used by the Japanese; they referred to ships by their name only.

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His/Her Majesty's Ship. A commissioned ship in the Royal Navy of Great Britain, i.e. HMS Hood. Also used by other nations with hereditary or constitutional monarchs, such as Sweden.

I

Imperial Japanese Navy. Used as a suffix to an officer's name, as in "Commander Fuchida, IJN", to indicate service in the Japanese navy

J

K

L

M

N

O

P

The left side of a vessel, marked by red navigation lights. Port (nautical)

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When speaking or writing about a ship, it is customary to use a prefix ahead of the ship's name, such as "USS Ship." This indicates both the nationality and status of the ship. Some navies, particularly the Japanese and German navies during World War 2, do not routinely use prefixes when referring to their ships. However, standard prefixes have been defined for use by speakers and authors who wish to use them for the sake of consistency.

It should be noted that prefixes are only used for ships that have been commissioned into their respective fleets; pre-commissioned or decommissioned ships are not referred to with prefixes, although some countries have established special prefixes for use in these cases (PCU, "pre-commissioning unit", in the United States, for example).

Usually, the ship's prefix (and, optionally, it's designator) is used the first time it is mentioned; afterward, only the ship's name is used. For example: "CV-1 USS Langley was the Navy's first aircraft carrier... Later, Langley was assigned..." In lists of task force composition and ship classes, the prefix may often be omitted in favor of the ship's designator, as in "CV-1 Langley". Ship prefix

A complete list of prefixes used on this site can be seen below.

Country	Ship Prefix	Definition	Country	Ship Prefix	Definition
Argentina	ARA	Armada de la Republica Argentina	Britain	HMS	His/Her Majesty's Ship
Canada	HMCS	His/Her Majesty's Canadian Ship	Denmark	HDMS/KDM	His/Her Danish Majesty's Ship/Kongelige Danske Marine
France	FS	French Ship, NATO designation. France does not use ship prefixes.	Germany - WWII	DKM	Deutsche Kriegsmarine, unofficial
Germany - Postwar	FGS	Federal German Ship, NATO designation. Germany does not use prefixes.	Iceland	V/s	Varðskip, Icelandic - Guard Ship (Coast Guard)
Italy	RN/NMM	Regia Nave, pre-1946; Nave Marina Militare, post-1946	Japan - WWII	HIJMS	His Imperial Japanese Majesty's Ship, unofficial
Japan - Postwar	JDS	JMSDF (Japanese Maritime Self Defense Force) Defense Ship	Mexico	ARM	Armada de la República Mexicana
Netherlands	HNLMS (Hr.Ms./Zr.Ms.)	His/Her Netherlands Majesty's Ship (Harer Majesteits/Zijner Majesteits)	Pakistan	PNS	Pakistani Naval Ship
Peru	BAP	Buque Armada Peruana	Poland	ORP	Okret Rzeczypospolitej Polskiej
Russia: Post-Berlin Wall	RFS	Russian Federation Ship, unofficial	Spain	SPS	Spanish Naval Ship
Taiwan	ROCS	Republic of China Ship	Turkey	TCG	Türkiye Cumhuriyeti Gemisi
United States	USS	United States Ship (military owned and operated)	United States	USNS	United States Naval Ship (military owned, but with a civilian crew. Used mostly by replenishment vessels - oilers, supply ships, etc.)
Uruguay	ROU	Republica Oriental del Uruguay

Q

R

Enlisted personnel carry "rates" (pay grade) and "ratings" (occupational specialty); officers have "rank".

S

The right side of a vessel, marked by green navigation lights. Starboard

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The back end of a boat or ship.

T

U

UNderway REPlenishment. The transfer of fuel and supplies between ships while both are underway, usually by means of hoses and cables strung between the vessels.

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United States Navy. Most often used as a suffix to a Naval member's name, as in Adm. Chester Nimitz, USN.

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United States Ship. A commissioned combat ship in the United States Navy, i.e. USS Nimitz. Ships that are not commissioned and most non-combatant ships (hospital ships, for example) do not receive the USS prefix. They may receive the prefix USNS (United States Naval Ship) to distinguish military-owned/civilian-crewed ships from civilian-owned vessels contracted to the Navy.

V

VERTical REPlenishment. Resupply by means of helicopters, performed both underway and at anchor. Used for all types of supplies except fuel.

W

Any deck on a ship that is permanently exposed to the elements.

X

Y

Z

Used to refer to Greenwich Mean Time (GMT). Many military installations, particularly communications sites, maintain a standard time, regardless of their location. This facilitates coordination of activities. "Greenwich" refers to Greenwich, England, located at Longitude 0. Coordinated Universal Time

About The Carrier Project
General Site Organization	Page Layout	Technology
Site Conventions	General Information	The Site Refit
Images	Ship Class Data	The Site Refit (Older Notes)
Glossary: Words and Abbreviations	Individual Ship Data	List of Page Dedications

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